1. CGE Training Materials National Greenhouse Gas Inventories Waste Sector Version 2, April 2012 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

2. These training materials are suitable for people with beginner to intermediate level knowledge of national greenhouse (GHG) inventory development. After having read this Presentation, in combination with the related documentation, the reader should: a)Have an overview of how emissions inventories are developed for the waste sector; b)Have a general understanding of the UNFCCC and IPCC guidelines; c)Be able to determine which methods suits their country’s situation best; d)know where to find more detailed information on the topic discussed. These training materials have been developed primarily on the basis of methodologies developed by the IPCC; hence the reader is always encouraged to refer to the original documents to obtain further detailed information on a particular issue. Target Audience and Objective from Training Materials 2 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

3. Acronyms BODBiochemical oxygen demand DOCDegradable Organic Carbon EFDBIPCC Emission Factor Database GHGGreenhouse Gas GPGGood Practice Guidance MSWMunicipal Solid Waste SWDSSolid Waste Disposal Site 3 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

4. Outline of course – Waste Sector Introduction (slide 5) Definitions (slide 7) Revised 1996 IPCC Guidelines (slide 29) Good Practice Guidance and Uncertainty Management in National Greenhouse Gas Inventories (slide 46) 4 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

5. GHG inventories for the biological sectors, such as waste, are characterized by: Methodological limitations Lack of data or low reliability of existing data High uncertainty. This presentation aims to assist non-Annex I (NAI) Parties in preparing GHG inventories using the Revised 1996 IPCC Guidelines, particularly in the context of UNFCCC decision 17/CP.8, focusing on: The need to shift to the IPCC good practice guidance (2000) and higher tiers/methods to reduce uncertainty Complete overview of the tools and methods Use of UNFCCC inventory software and EFDB Review of activity data and emission factors and options to reduce uncertainty Use of key sources, methodologies and decision trees. Introduction 5 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

6. NAI Party examples Examination of national communications GHG inventories show that the waste sector may be significant in NAI countries Commonly a significant source of CH 4 In some cases, a significant source of N 2 O Solid waste disposal sites (SWDS) frequently a key source of CH 4 emissions. 6 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

7. Definitions Waste emissions – Includes GHG emissions resulting from waste management activities (solid and liquid waste management, excepting CO 2 from organic matter incinerated and/or used for energy purposes). Source – Any process or activity that releases a GHG (such as CO 2, N 2 O, CH 4 ) into the atmosphere. 7 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

8. Definitions (cont.) Activity Data – Data on the magnitude of human activity, resulting in emissions during a given period of time (e.g. data on waste quantity, management systems and incinerated waste). Emission Factor – A coefficient that relates activity data to the amount of chemical compound that is the source of later emissions. Emission factors are often based on a sample of measurement data, averaged to develop a representative rate of emission for a given activity level under a given set of operating conditions. 8 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

9. Revised 1996 IPCC Guidelines and IPCC good practice guidance (2000) Approach and steps 9 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

10. Decomposition of organic matter in wastes (carbon and nitrogen) Waste incineration (these emissions are not reported when waste is used to generate energy). Emissions from Waste Management 10 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

11. Decomposition of Waste Anaerobic decomposition of man-made waste by methanogenic bacteria a)Solid waste Land disposal sites b)Liquid waste Human sewage Industrial waste water. Nitrous oxide emissions from waste-water are also produced from protein decomposition. 11 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

12. Land Disposal Sites Major form of solid waste disposal in developed world Produces mainly methane at a diminishing rate, taking many years for waste to decompose completely Also carbon dioxide and volatile organic compounds produced Carbon dioxide from biomass not accounted or reported elsewhere. 12 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

13. Decomposition Process Organic matter into small soluble molecules (including sugars) Broken down to hydrogen, carbon dioxide and different acids Acids are converted to acetic acid Acetic acid with hydrogen and carbon dioxide are substrate for methanogenic bacteria. 13 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

14. Volumes Estimates from landfills: 20–70 Tg/yr Total human methane emissions: 360 Tg/yr From 6% to 20% of total. Other impacts Vegetation damage Odours May form explosive mixtures. Methane from Land Disposal 14 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

15. Highly heterogeneous However, relevant factors to consider: Waste management practices Waste composition Physical factors. Characteristics of the Methanogenic Process 15 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

16. Waste Management Practices Aerobic waste treatment Produces compost that may increase soil carbon No methane. Open dumping Common in developing regions Shallow, open piles, loosely compacted No control for pollutants, scavenging frequent Anecdotal evidence of methane production An arbitrary factor, 50% of sanitary land filling, is used. 16 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

17. Sanitary landfills Specially designed Gas and leakage control Scale economy Continued methane production. Waste Management Practices (cont.) 17 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

18. Degradable organic matter can vary: Highly putrescible in developing countries In developed countries, due to higher paper and card content, less putrescible. This affects stabilization and methane production: Developing countries: 10–15 years Developed countries: more than 20 years. Waste Composition 18 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

19. Moisture essential for bacterial metabolism: Factors: initial moisture content, infiltration from surface and groundwater, as well as decomposition processes. Temperature: 25–40°C required for a good methane production. Physical Factors 19 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

20. Chemical conditions Optimal pH for methane production: 6.8 to 7.2 Sharp decrease of methane production below 6.5 pH Acidity may delay the onset of methane production. Conclusion Data availability is too poor to use these factors for national or global methane emissions estimates. Physical Factors (cont.) 20 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

21. Methane Emissions Depend on several factors Open dumps require other approaches Availability and quality of relevant data. 21 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

22. Wastewater Treatment Produces methane, nitrous oxide and non-methane volatile organic compounds May lead to storage of carbon through eutrophication. 22 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

23. From anaerobic processes without methane recovery Volumes 30–40 Tg/yr About 8%–11% of anthropogenic methane emissions Industrial emissions estimated at 26–40 Tg/yr Domestic and commercial estimated at 2 Tg/yr. Methane Emissions from Wastewater Treatment 23 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

24. Biochemical oxygen demand (BOD) (+/+) Temperature ( >15°C) Retention time Lagoon maintenance: Depth of lagoon ( >2.5 m, pure anaerobic; less than 1 m, not expected to be significant, most common facultative 1.2 to 2.5 m – 20% to 30% BOD anaerobically). Factors for Methane Emissions 24 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

25. Is the organic content of wastewater (“loading”) Represents oxygen consumed by waste water during decomposition (expressed in mg/l) Standardized measurement is the “5-day test” denoted as BOD 5 Examples of BOD 5 : Municipal waste water 110–400 mg/l Food processing 10 000–100 000 mg/l. Biochemical Oxygen Demand 25 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

26. Main Industrial Sources Food processing: Processing plants (fruit, sugar, meat, etc.) Creameries Breweries Others. Pulp and paper. 26 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

27. Waste Incineration Waste incineration can produce: Carbon dioxide, methane, carbon monoxide, nitrogen oxides, nitrous oxides and non-methane volatile organic compounds Nevertheless, it accounts for a small percentage of GHG output from the waste sector. 27 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

28. Only the fossil-based portion of waste to be considered for carbon dioxide Other gases difficult to estimate: Nitrous oxide mainly from sludge incineration. Emissions from Waste Incineration 28 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

29. Revised 1996 IPCC Guidelines Basis of inventory methodology for waste sector is: Organic matter decomposition Incineration of fossil origin organic material Does not include concrete calculations for the latter Organic matter decomposition covers: Methane from organic matter in both liquid and solid wastes Nitrous oxide from protein in human sewage Emissions of non-methane volatile organic compounds are not covered. 29 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

30. IPCC Default Categories Methane Emissions from Solid Waste Disposal Sites Methane Emissions from Wastewater treatment: Domestic and Commercial Wastewater Industrial Wastewater and Sludge Streams Nitrous oxide from Human Sewage. 30 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

31. Inventory Preparation using Revised 1996 IPCC Guidelines Step 1: Conduct key source category analysis for waste sector where: a)Sector is compared to other source sectors such as energy, agriculture, LULUCF, etc. b)Estimate waste sector’s share of national GHG inventory c)Key source sector identification adopted by Parties that have already prepared an initial national communication, have inventory estimates d)Parties that have not prepared an initial national communication can use inventories prepared under other programmes/projects e)Parties that have not prepared any inventory, may not be able to carry out the key source sector analysis. Step 2: Select the categories 31 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

32. Inventory Preparation using Revised 1996 IPCC Guidelines (cont.) Step 3: Assemble required activity data depending on tier selected from local, regional, national and global databases, including EFDB Step 4: Collect emission/removal factors depending on tier level selected from local/regional/national/global databases, including EFDB Step 5: Select method of estimation based on tier level and quantify emissions/removals for each category Step 6: Estimate uncertainty involved Step 7: Adopt quality assurance/control procedures and report results Step 8: Report GHG emissions Step 9: Report all procedures, equations and sources of data adopted for GHG inventory estimation. 32 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

33. For sanitary landfills there are several methods: a)Mass balance and theoretical gas yield b)Theoretical first order kinetics methodologies c)Regression approach. Complex models not applicable for regions or countries. Open dumps considered to emit 50%, but should be reported separately. Calculation of Methane from Solid Waste Disposal 33 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

34. No time factors Immediate release of methane Produces reasonable estimates if amount and composition of waste have been constant or slowly varying, otherwise biased trends How to calculate: a)Using empirical formulae b)Using degradable organic content. Mass Balance and Theoretical Gas Yield 34 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

35. Assumes 53% of carbon content is converted to methane If microbial biomass is discounted it reduces the amount emitted 234 m 3 of methane per tonne of wet municipal solid waste. Empirical Formulae 35 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

36. Calculated from the weighted average of the carbon content of various components of the waste stream Requires knowledge of: a)Carbon content of the fractions b)Composition of the fractions in the waste stream This method is the basis for the Tier I calculation approach. Using Degradable Organic Content (Basis for Tier 1) 36 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

37. Equation Methane emissions = Total municipal solid waste (MSW) generated (Gg/yr) x Fraction landfilled x Fraction degradable organic carbon (DOC) in MSW x Fraction dissimilated DOC x 0.5 g C as CH 4 /g C as biogas x Conversion ratio (16/12) ) – Recovered CH 4 37 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

38. Assumptions Only urban populations in developing countries need be considered; rural areas produce no significant amount of emissions. Fraction dissimilated was assumed from a theoretical model that varies with temperature: 0.014T + 0.28, considering a constant 35°C for the anaerobic zone of a landfill, this gives 0.77 dissimilated DOC. No oxidation or aerobic process included. 38 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

39. Example Waste generated 235 Gg/yr % landfilled 80 % DOC 21 % DOC dissimilated 77 Recovered 1.5 Gg/yr Methane = (235*0.80*0.21*0.77*0.5*16/12) – 1.5 =19 Gg/yr 39 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

40. Limitations Main: a)No time factor b)No oxidation considered DOC dissimilated too high Delayed release of methane under increasing waste landfilled conditions leads to significant overestimations of emissions Oxidation factor may reach up to 50% according to some authors, a 10% reduction is to be accounted. 40 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

41. Default Method – Tier 1 a)Includes a methane correction factor according to the type of site (waste management correction factor). Default values range from 0.4 for shallow unmanaged disposal sites (> 5m) to 0.8 for deep (<5m) unmanaged sites; and 1 for managed sites. Uncategorized sites given a correction factor of 0.6 b)The former DOC dissimilated was reduced from 0.77 to 0.5 – 0.6, due to the presence of lignin. 41 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

42. Default Method – Tier 1 The fraction of methane in landfill gas was changed from 0.5 to a range between 0.4 and 0.6, to account for several factors, including waste composition. Includes an oxidation factor. Default value of 0.1 is suitable for well managed landfills. It is important to remember to subtract recovered methane before applying an oxidation factor. 42 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

43. Emissions of methane (Gg/yr) = [(MSW T *MSW F *L 0 ) -R]*(1-OX) where MSW T = Total municipal solid waste MSW F = Fraction disposed at SWDS L 0 = Methane generation potential R = Recovered methane (Gg/yr) OX = Oxidation factor (fraction) Default method – Tier 1 good practice example 43 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

44. L 0 = (MCF*DOC*DOC F *F*16/12 (GgCH 4 /Gg waste)) where: MCF = Methane correction factor (fraction) DOC = Degradable organic carbon DOC F = Fraction of DOC dissimilated F = Fraction by volume of methane in landfilled gas 16/12 = Conversion from C to CH 4 Methane Generation Potential 44 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

45. Other Approaches Include a fraction of dry refuse in the equation Consider a waste generation rate (1 kg per capita per day for developed countries; half of that for developing countries) Use gross domestic product (GDP) as an indicator of waste production rates. 45 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

46. IPCC Good Practice Guidance Approach 46 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

47. Tier 2 considers the long period of time involved in organic matter decomposition and methane generation. Main factors: a)Waste generation and composition b)Environmental variables (moisture content, pH, temperature and available nutrients) c)Age, type and time since closure of landfill. Theoretical First Order Kinetics Methodologies (Tier 2) 47 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

48. Base Equation Q CH4 = L 0 R(e -kc - e -kt ) Q CH4 = methane generation rate at year t (m 3 /yr) L 0 = degradable organic carbon available for methane generation (m 3 /tonne of waste) R = quantity of waste landfilled (tonnes) k = methane generation rate constant (yr -1 ) c = time since landfill closure (yr) t = time since initial refuse placement (yr) 48 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

49. Good Practice Equation Time t is replaced by t-x, a normalization factor that corrects for the fact that the evaluation for a single year is a discrete time rather than a continuous time estimate Methane generated in year t (Gg/yr) =  x [(A*k*MSW T (x)*MSW F (x)*L 0 (x)) * e -k(t-x) ] for x = initial year to t Sum the obtained results for all years (x). 49 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

50. Good Practice Equation (cont.) Where: t = year of inventory x = years for which input should be added A = (1-e -k )/k; normalisation factor which corrects the summation k = Methane generation rate constant MSW T (x)= Total municipal solid waste generated in year x (Proportional to total or urban population if no rural waste collection) L 0 (x) = Methane generation potential 50 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

51. The methane generation rate constant, k, is the time taken for the DOC in waste to decay to half its initial mass (half-life) k = ln2/t ½ This requires historical data. Data for 3 to 5 half lives in order to achieve an acceptable result. Changes in management should be taken into account. Methane Generation Rate Constant 51 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

52. Is determined by type of waste and conditions Measurements range from 0.03 to 0.2 per year, equivalent to half lives from 23 to 3 years The more degradable material and humidity, the lower the half life Default value: 0.05 per year, or a half life of 14 years. Methane Generation Rate Constant 52 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

53. L 0 (x) = (MCF(x)*DOC(x)*DOC F *F*16/12 (GgCH 4 /Gg waste)) where: MCF(x) = Methane correction factor in year x (fraction) DOC (x) = Degradable organic carbon in year x DOC F = Fraction of DOC dissimilated F = Fraction by volume of methane in gas generated from landfill 16/12 = Conversion from C to CH 4 Methane Generation Potential 53 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

54. Methane Emitted Methane generated minus methane recovered and not oxidized Equation: Methane emitted in year t (Gg/yr) = (Methane generated in year t (Gg/yr) - R(t))*(1 - Ox) Where: R(t) = Methane recovered in year t (Gg/yr) Ox = Oxidation factor (fraction) 54 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

55. Practical Applications Base for Tier 2 approach Applied earlier in: a)United Kingdom b)The Netherlands c)Canada. 55 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

56. Regression Approach From empirical models Statistical and regressional analysis applied. 56 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

57. Methane actually produced: Are old landfills covered? Quantity and composition of landfilled waste: Is there historical data on waste composition? Methane actually produced: Are landfill and waste management practices well known? Uncertainties in Calculations 57 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

58. Calculations for industrial and domestic and commercial waste water are based on biochemical oxygen demand (BOD) loading Standard methane conversion factor 0.22 Gg CH 4 /Gg BOD is recommended For nitrous oxide and methane it is possible to base calculation on total volatile solids and apply the simple method used in the agriculture sector. Calculations of Emissions from Wastewater Treatment 58 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

59. Simplified approach Data: a)BOD in Gg per 1000 persons (default values) b)Country population in thousands c)Fraction of total waste water treated anaerobically (0.1–0.15 as default) d)Methane emission factor (default 0.22 Gg CH 4 /Gg BOD e)Subtract recovered methane. Methane from Domestic and Commercial Wastewater 59 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

60. Equation Methane emission = Population (10 3 ) x Gg BOD 5 /1000 persons x Fraction anaerobically treated x 0.22 Gg CH 4 /Gg BOD – Methane recovered 60 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

61. WM = P*D*SBF*EF*FTA*365*10 -12 Where: WM = country’s annual methane emissions from domestic waste water P = population (total or urban in developing countries) D = organic load (default 60 g BOD/person/day) SBF = fraction of BOD that readily settles, default = 0.5 EF = emission factor (g CH 4 / g BOD), default = 0.6 or 0.25 g CH 4 / g COD (chemical oxygen demand) when using COD FTA = part of BOD anaerobically degraded, default = 0.8 Good Practice Guidance – Check Method 61 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

62. Check Method Rationale SBF is related to BOD from non-dissolved solids, which account for more than 50% of BOD. Settling tanks remove 33% and other methods 50%. Fraction of BOD in sludge that degrades anaerobically (FTA) is related to the processes, aerobic or anaerobic. Aerobic processes and sludge non-methane producing procedures may lead to FTA = 0 62 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

63. Check Method Rationale Emission factor is expressed in BOD; however COD is used for many purposes COD is 2 to 2.5 times higher than BOD, so the default values are 0.6 g CH 4 / g BOD or 0.25 g CH 4 / g COD Emission factor is calculated from the methane producing factor stated above and the weighted average of methane conversion factor (MCF). 63 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

64. IPCC guidelines recommends separate calculations for wastewater and sludge. This influences the detailed approach calculation. Apart from sludge sent to landfills or for agriculture, this is not necessary. If no data are available, expert judgement of sanitation engineers may be incorporated: Weighted MCF = Fraction of BOD anaerobically degrades. Methane Conversion Factor 64 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

65. Considers two additional factors: a)Different treatment methods used and total waste water treated using each method b)MCF for each treatment. The final result is the sum of the fractions calculated by the simplified approach, less the recovered methane. Detailed Approach 65 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

66. Equation Domestic and commercial waste-water emissions = (   Methane calculated by simplified approach x Fraction waste water treated using method i x MCF for method i) - methane recovered 66 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

67. 67 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

68. Industrial wastewater may be treated in domestic sewer systems or on site Only on-site calculations are covered in this section, the rest should be added to domestic wastewater loading Most estimates used are for point sources Focus on key industries is required and default values are provided. Methane Emissions from Industrial Wastewater 68 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

69. Simplified approach: Determine relevant industries (wine, beer, food, paper, etc.) Estimate wastewater outflow (per tonne of product, or default) Estimate BOD 5 concentration (or default) Estimate the fraction treated Estimate methane emission factor (default 0.22 Gg CH 4 /Gg BOD ) Subtract any methane recovered. Emissions from Industrial Wastewater Treatment 69 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

70. Equation Industrial wastewater emissions = (    wastewater outflow by industry (Ml/yr) x kg BOD 5 /I x Fraction wastewater treated anaerobically x 0.22) - Methane recovered 70 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

71. Similar to the approach used for estimating methane emissions from domestic and commercial wastewater. Requires knowledge of: a)Specific wastewater treatments b)MCF for each factor. Detailed Approach 71 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

72. Equation Industrial wastewater Emissions = (    Wastewater outflow by industry (Ml/yr) x kg BOD 5 /l x Fraction wastewater treated using method i x MCF for method i) - Methane recovered 72 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

73. a)Lack of information about volumes, treatments and recycling b)Discharge into surface waters: Not anaerobic (default 0%) Anaerobic (default 50%) c)Septic tanks (long retention times: more than 6 months) Long retention of solids (default 50%) Short retention of solids (default 10%) d)Open pits and latrines (default 20%) e)Other limitations: BOD, temperature, pH and retention time. Uncertainties in Calculations 73 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

74. For carbon dioxide, only fossil fraction counts, not biomass Only accounted under waste sector when no energy is recovered IPCC good practice guidance include a simple method a)It is good practice to disaggregate waste into waste types and take into account burn-out efficiency of incinerator. Emissions from Waste Incineration 74 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

75. 75 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

76. CO 2 emission (Gg/yr) =  i (IW i *CCW i *FCF i *Ef i *44/12) Where: i = MSW, HW, CW, SS MSW municipal solid waste, HW hazardous waste, CW clinical waste and SS sewage sludge IW i = Amount of incinerated waste type i CCW i = Fraction of carbon content in waste type i FCF i = Fraction of fossil carbon in waste type i EF = Burn-out efficiency of combustion of incinerators for waste type i (fraction) 44/12 = Conversion from carbon to CO 2 Equation for Carbon Dioxide 76 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

77. N 2 O emission (Gg/yr) =  i (IW i *Ef i )*10 -6 where IW i = Amount of incinerated waste type i (Gg/yr) EF i = Aggregate emission factor for waste type i (kg N 2 O/Gg) or N 2 O emission (Gg/yr) =  i (IW i *EC i *FGV i )*10 -9 IW i = Amount of incinerated waste type i (Gg/yr) EC i = N 2 O emission concentration in flue gas from waste of type i (mg N 2 O /Mg) FGV i = Flue gas volume by amount of incinerated waste type i (m 3 /Mg) Equation for Nitrous Oxide 77 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

78. Carbon content varies: sewage sludge, 30%; municipal solid waste, 40%; hazardous waste, 50%; and clinical waste, 60%. It is assumed that there is very little > fossil carbon in sewage sludge, 0%; high content in clinical and municipal, 40%; and very high content in hazardous waste, 90%. The efficiency of combustion is 95% for all waste streams, except hazardous, which is 99.5%. Emission Factors and Activity Data for Carbon Dioxide 78 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

79. Emission factors differ with facility type and type of waste Default factors can be used Consistency and comparability are difficult due to heterogeneous waste types across countries. Emission Factors and Activity Data for Nitrous Oxide 79 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

80. It is good practice to document and archive all information required to produce the national inventory estimates See GPG2000, Chapter 8, Quality Assurance and Quality Control, Section 8.10.1, Internal Documentation and Archiving Transparency in activity data and the possibility to retrace calculations are important. Reporting Framework: General Recommendations 80 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

81. Transparency can be improved through clear documentation and explanations: a)Estimate using different approaches b)Cross-check emission factors c)Check default values, survey data and secondary data preparation for activity data d)Cross-check with other countries. Involve industry and government experts in review processes. Report Quality Assurance/Quality Control 81 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

82. a)If Tier 2 is applied, historical data and k values should be documented, and closed landfills should be accounted for b)Distribution of waste (managed and unmanaged) for MCF should be documented c)Comprehensive landfill coverage, including industrial, sludge disposal, construction and demolition waste sites is recommended. Reporting for Methane from Solid Waste Disposal Sites 82 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

83. If methane recovery is reported, an inventory is desirable. Flaring and energy recovery should be documented separately. Changes in parameters should be explained and referenced. Time series should apply the same methodology; if there are changes it is required to recalculate the entire time series to achieve consistency in trends (See GPG2000, Chapter 7, 7.3.2.2, Alternative recalculation techniques). Reporting for Methane from Solid Waste Disposal Sites 83 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

84. Reporting for Methane from Domestic Wastewater Handling Function of human population and waste generation per person, expressed as biochemical oxygen demand If in rural areas, only aerobical disposal; only urban population is accounted for COD*2.5 = BOD Recalculate whole time series Calculations need to be retraced, particularly if there are changes to MCFs. 84 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

85. Industrial estimates are accepted if they are transparent and consistent with QA/QC Recalculations need to be consistent over time Default data for industrial waste water is in GPG2000, Chapter 5, Table 5.4 Sectoral tables and a detailed inventory report are necessary to provide transparency. Reporting for Methane from Industrial Wastewater Handling (cont.) 85 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

86. Reporting Nitrous Oxide Emissions from Wastewater Based on the Revised 1996 IPCC Guidelines, Chapter 4, Agriculture, Section 4.8, Indirect N 2 O emissions from nitrogen used in agriculture Future work on data, approaches and calculations is needed. 86 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

87. All waste incineration is to be included Avoid double counting with energy recovery, even when waste is used as a substitute fuel (e.g. cement and brick production) Default ranges for emission estimates are provided in GPG2000, Chapter 5, Tables 5.6 and 5.7 Support fuel, generally little, shall be reported in the energy sector; may be important for hazardous waste. Reporting for Waste Incineration 87 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

88. Comparison Between Revised 1996 IPCC Guidelines and IPCC Good Practice Guidance IPCC good practice guidanceRevised 1996 IPCC Guidelines - default approach First Order Decay Method for Solid Waste Disposal Sites based on real-world conditions of decomposition Based on last year’s waste entering the disposal sites. Good approximation only for long-term stable conditions. First Order Decay is mentioned without specific calculations Includes a “check method” for countries with difficulties to calculate the emissions from domestic waste-water handling Keeps a separation between:  Domestic waste water  Industrial waste water Human sewage is indicated as an area for further development and no improvement over IPCC 1996GL is presented Calculation made on the basis of an approximation developed for the Agriculture sector (see chapter on Agriculture sector) New section including emissions from waste incineration covers:  CO 2 emissions  N 2 O emissions Contains no detailed methodologies 88 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

89. Comparison of Key Activity Data Required IPCC good practice guidanceRevised 1996 IPCC Guidelines  Disposal activity for solid waste for several years  Less requirements with the check method for CH 4 emissions from domestic waste water  Top-down modification of IPCC 1996GL recommended due to high costs  Incineration amounts, composition (carbon content and fossil fraction) required for CO 2  Emission measurements recommended for N 2 O  Disposal activity for current year, default values or a per capita approach  Waste-water flows and waste-water treatment data required  Very detailed, industry specific data required  No specific methodology 89 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

90. Comparison of Key Emission Factors Required Most emission factors are common to both IPCC 1996 GL and GPG 2000: Methane generation potential for SWDS Human sewage conversion factor Methane conversion factor. New emission factors related to: Tier 2 for SWDS, particularly k value Waste incineration (lack of some default values). 90 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

91. Link Between IPCC 1996 GL and GPG 2000 GPG 2000 uses the same tables as were provided in IPCC 1996GL, based on the same categories. 91 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

92. Problems found by NAI experts when using IPCC 1996 GL Problems categorized into: Methodological issues Activity data Emission factors. GPG2000 addresses some deficiencies found in IPCC 1996 GL: Strategies for improvement in methodology, activity data and emission factors Strategy for activity data and emission factors – tier approach Sources of data for activity data and emission factors, including EFDB. Problems Addressed 92 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

93. Methodological Issues Methodologies that are not covered : Sludge spreading and composting, Use of burning under conditions not reflected properly in the waste incineration section Tropical conditions of many NAI Parties vis-à-vis methane generation Use of open dumps instead of landfills Lack of a proper calculation method for human sewage in the case of island countries or countries with prevailing coastal populations, and complexity of the methodology. 93 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

94. IPCC good practice guidance approachImprovement suggested -The GPG 2000 does not cover composting and sludge spreading, which are common practices in NAI countries -Burning and open dump processes are not well covered by GPG 2000 and are frequent practices in NAI countries. - Initiate field studies to generate methodologies, or use approaches proposed by Annex I countries for these categories. - Expand the proper sections to reflect the conditions prevailing in many NAI countries. Lack of Waste Methodologies that Reflect National Circumstances 94 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

95. IPCC good practice guidance approachImprovement suggested -The GPG 2000 does not cover conditions for tropical countries and management practices for both solid wastes and wastewaters -The approximation used in GPG 2000 to calculate nitrous oxide from human sewage (the same approximation as in IPCC 1996 GL) does not reflect properly the situation of coastal/island areas -Initiate field studies to expand the methodology -Adopt the proposed methodologies covered in the agriculture chapter differentiating according to geographical reality More Deficiencies in the Methodologies 95 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

96. Complexity of Methodology IPCC good practice guidance approachImprovement suggested -The methodologies presented for Solid Waste Disposal Sites and Waste Incineration require data that are not commonly available in NAI countries -Methods similar to the Check method for waste water should be provided to enhance completeness of reporting 96 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

97. Activity Data Problems 97 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE) Inadequate data on generated solid waste Inadequate time-series data for waste generation Non-availability of disaggregated data Inadequate data on composition of solid waste Inadequate data on oxidation conditions Extrapolations based on past data used to apply Tier 2 for Solid Waste Disposal Sites CH 4 generation Low reliability and high uncertainty of data

98. Emission Factor Problems 98 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE) Inappropriate default values given in IPCC 1996 GL Default data not suitable for national circumstances Lack of emission factors at disaggregated level Lack of availability of methane conversion factors for certain NAI regions Low reliability and high uncertainty of data Lack of emission factors in IPCC 1996 GL for waste incineration (covered by GPG 2000) Default data commonly provides upper value, leading to overestimation

99. List of problems,by category 99 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

100. Methodological issues: Use of open dumps or open incineration Recycling, commonly of wood and paper but even of organic waste. CH 4 Emissions from Solid Waste Disposal Sites, Table 6.A 100 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

101. Lack of activity data, both for the present and the required time series, for the waste flows and their composition Default activity data for only 10 NAI countries Values reflected for k parameter for the application of the First Order Decay method do not reflect tropical conditions of temperature and humidity. The higher k value in GPG 2000 is 0.2 and the one in IPCC 1996 GL is 0.4 The proposed Methane Correction Factor, even using the lesser value, 0.4, may lead to overestimations, due to shallowness and the frequent practice of burning as a pretreatment at disposal sites. Activity Data and Emission Factors 101 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

102. Emissions from Wastewater Handling, Table 6.B Methodological issues For CH 4 emissions from domestic wastewater handling, GPG2000 presents a simplified method called the “check method” avoiding the complexities in IPCC 1996 GL. In NAI countries, national methods or parameters, or even activity data, may by available only infrequently. For CH 4 emissions from industrial waste-water handling, GPG2000 presents a “best practice” for cases where these emissions represent a key source, recommending the selection of 3 or 4 key industries. For emissions of N 2 O from human sewage, no improvements were made in GPG2000 over IPPC 1996 GL. This methodology has several limitations that have caused several NAI countries to declare it “inapplicable”. 102 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

103. Availability of activity data and emission factors is uncommon in NAI countries for CH 4 emissions from domestic wastewater, and the “check method” may help to overcome this issue. In any case, GPG 2000 is an improvement in that it identifies potential CH 4 emissions. For CH 4 emissions from industrial waste water, in cases where it is a key source, it is feasible to work only with the largest industries. For N 2 O emissions from human sewage, the activity data needed are relatively simple and easy to obtain. Activity Data and Emission Factors 103 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

104. Methodological issues This source category was only briefly introduced in the IPCC 1996GL, but is fully developed in GPG 2000. In NAI countries, incineration of waste (other than clinical waste) is uncommon due to high costs. Differentiation is made between CO 2 and N 2 O because the former is calculated with a mass balance approach and the latter depends on operating conditions. Emissions from Waste Incineration, Table 6.C 104 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

105. GPG2000 recognizes the difficulties in finding activity data to differentiate the four proposed categories (municipal, hazardous, clinical and sewage sludge). Do not request differentiation if data are not available when it is not a key source category. Activity Data and Emission Factors 105 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

106. The good practice approach requires that estimates of GHG inventories be accurate They should neither be over- nor underestimated as far as can be judged. Causes of uncertainty could include: Unidentified sources Lack of data Quality of data Lack of transparency. Uncertainty Estimation and Reduction 106 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

107. Main uncertainty sources: Activity data (total municipal waste MSW T and fraction sent to disposal sites MSW F ) Emission factors (methane generation rate constant). Other factors listed in GPG2000, Table 5.2: Degradable organic carbon, fraction of degradable organic carbon, methane correction factor, fraction of methane in landfill gas Possibly also methane recovery and oxidation factor. Reporting Uncertainties from Waste Disposal Sites 107 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

108. Uncertainty Estimation and Reduction Uncertainties are related to BOD/person, maximum methane producing capacity and fraction treated anaerobically (data for population has little uncertainty (+5%)). Default ranges are: BOD/person and maximum methane producing capacity (+ 30%). For fraction treated anaerobically use expert judgement. 108 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

109. Uncertainties are related to industrial production, COD/unit wastewater (from -50% to +100%), maximum methane producing capacity and fraction treated anaerobically. Default ranges are: industrial production (+ 25%) maximum methane producing capacity (+ 30%). For fraction treated anaerobically use expert judgement. Reporting Uncertainties from Industrial Wastewater Treatment 109 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

110. Activity data uncertainty on amount of incinerated waste assumed to be low (+5%) in developed countries. Some wastes, such as clinical waste, may be higher. Major uncertainty for CO 2 is fossil carbon fraction. For N 2 O default values, uncertainty is as high as 100%. Reporting Uncertainties from Waste Incineration 110 Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE)

111. Thank you! Training Materials for National Greenhouse Gas Inventories Consultative Group of Experts (CGE) 111